| Suzuki cross-coupling, one of the most inportant reactions for C–C formation, hasbecome increasingly popular due to its compatibility with a variety of functional groups,widly used in natural products, pharmaceuticals, agrochemicals and ligands forasymmetric synthesis and in new materials. Suzuki cross-coupling reaction usuallyrequires expensive organic solvents and homogeneous Pd catalysts. Although they havemany advantages, the difficulties surrounding the separation and recovery of the catalystrestrict their applications in certain industries. Heterogenization of the existinghomogeneous palladium catalysts offers an attractive solution to this problem.Diarylmethane derivatives, which are important building blocks in organic synthesis, canalso be obtained by Suzuki cross-coupling reactions with benzyl halides. However, theactivation of benzyl chlorides is particularly challenging and successful examples usingheterogeneous catalysis are quite rare.In this paper, we studied the preparation of microporous polymer supported Pd catalystsand their catalytic performance in Suzuki cross-coupling reaction with benzyl chloride.Firstly, catalysts were characterized by XPS, FT-IR, TEM, etc. Then, we screened out theoptimized reaction condition. The non-toxic aqueous media, mild reaction conditions,stability of the catalyst and the facile synthesis approach may eventually be helpful to useKAPs(Ph-PPh3)-Pd at industrial scale. Under this condition, a variety of substratesafforded fast convert and obtained a high yield of the target product, both electronwith-drawing and electron-donating substrates. In addition, during the reaction, it wasfound that phenylboronic acid self-coupling and benzyl chloride dechlorinationphenomenon took place when4-nitrylbenzyl chloride was used as the substrate. These problems could be solved by changing the reaction conditions and a better result wasultimately achieved, and the yield of products was more than90%. |
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